This invention relates to microporous powder from polylactides and to a process for their preparation. More particularly this invention relates to microporous polylactide powders which can have active substances such as medicaments, nutrients, plant growth regulating agents, fragrances and the like introduced therein and the resultant pore filled powders used for controlled dispensing of the active substance.
Processes are already known in which polylactides are dissolved in various solvents possibly in the presence of pore forming agents and the resultant solutions further worked up. The resultant procedures do not, however, provide tricklable microporous powders suitable for having incorporated into the powder particle structure active agents such as aforenoted.
When the polylactide is dissolved in benzene or toluene and the resultant solution cooled, there is obtained on the working up of the solution i.e., removal of the solvent, a solid transparent foil.
There exists therefore a necessity to provide an economically feasible, industrial process for preparing microporous polylactide powders having the improved properties as aforediscussed.